This invention relates to a plant for liquid treating tubular fabrics in general. Examples of treatments for which the plant is suitable are mercerisation, washing in general, dyeing and other treatments of tubular fabrics with liquids. The invention will be described with particular reference to the mercerisation of tubular fabrics.
Mercerisation is notably a chemical treatment to which the yarn of cotton, linen and hemp fabrics is subjected, consisting of impregnating the semi-finished articles under tension with an alkaline solution, then washing the yarn or fabric to completely remove the soda. As a result of the swelling action of the alkalis, mercerisation opens the macromolecular structure of the fibres, which swell and become rounded, assuming a lustre and a capacity of uniformly absorb a dye.
In particular in the case of fabrics, to which the present invention relates, modern technology has conceived mercerisation plants comprising members of various kinds for imparting the necessary tension to the fabric, soda impregnation tanks, wash tanks and rinsing tanks through which the fabric is passed in succession. These plants extend mainly in a horizontal direction and occupy a large surface area, over which the various treatment stations are distributed in series. As stated, the main items are series-disposed tanks.
The plants existing at the present time are especially constructed for mercerisation of flat or open fabrics. When it is required to mercerise a tubular fabric, at present it is often necessary to cut the fabric, mercerise it and then re-sew it to reform the tubular structure.
It is apparent that this treatment has very negative consequences on the quality of the fabric, as a tubular fabric originally manufactured without seams comprises, after mercerisation, a longitudinal seam which interrupts the unity of the fabric, besides all the disadvantages which the seam itself presents.
Tubular fabrics are therefore in practice not mercerised in a satisfactory manner, with the result that the dyeing of the tubular fabric is not carried out or is not properly successful. This situation has given rise to the need to conceive a mercerisation plant of new and original construction, able to overcome the aforesaid disadvantage, i.e. able to mercerise tubular fabrics without in any way disrupting their unity or uniformity.
Similar considerations apply for other liquid treatments of tubular fabrics.